12001221111 has 16 divisors (see below), whose sum is σ = 18483164928. Its totient is φ = 6845616000.

The previous prime is 12001221059. The next prime is 12001221137. The reversal of 12001221111 is 11112210021.

It is not a de Polignac number, because 12001221111 - 2⁹ = 12001220599 is a prime.

It is a super-2 number, since 2×12001221111² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12001221511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10695715 + ... + 10696836.

It is an arithmetic number, because the mean of its divisors is an integer number (1155197808).

Almost surely, 2^12001221111 is an apocalyptic number.

12001221111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

12001221111 is a deficient number, since it is larger than the sum of its proper divisors (6481943817).

12001221111 is a wasteful number, since it uses less digits than its factorization.

12001221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21392582.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 12001221111 its reverse (11112210021), we get a palindrome (23113431132).

The spelling of 12001221111 in words is "twelve billion, one million, two hundred twenty-one thousand, one hundred eleven".